The present invention relates to magnetic memory and magnetic storage devices, and more specifically, to linear magnetoresistive random access memory devices (MRAM) with self-aligned bottom contacts.
Unlike conventional RAM chip technologies, data in MRAM is not stored as electric charge or current flows, but by magnetic storage elements. The magnetic storage elements are formed from two ferromagnetic plates, each of which can hold a magnetization, separated by a thin insulating layer. One of the two ferromagnetic plates is a permanent magnet set to a particular polarity, while the other plate has a magnetization that can be changed to match that of an external field or that can be changed using an applied current to store memory. This configuration is known as a magnetic tunnel junction and is the simplest structure for an MRAM bit/cell. A memory device is built from a grid of such cells.